Audio RightMark: "The RMAA suite is designed for testing quality of analog and digital paths of any audio devices, be it a sound card, an MP3 player, a consumer CD/DVD player or an acoustic set. The results are obtained by playing and recording test signals passed through the tested audio path by means of frequency analysis algorithms."
If you can't afford spending thousands of dollars on dedicated test equipment, the Rightmark RMAA might be the solution and it is free!
Using a high quality soundcard it performs noise, THD, IMD measurements to the limits of the soundcards abilities. With the Soundblaster Audigy I am able to resolve noise and distortion products below -90db.
3.5mm stereo TRS to 2x RCA
It's easy to use, you only need 2 cables: Soundcard to Amplifier and back to the Soundcard...
The ARTA Software consists of three programs: ARTA, STEPS and LIMP.
They are tools for audio measurements and analysis in acoustical and communication systems.
is a program for the impulse response measurement, for real-time spectrum analysis and for real-time frequency response measurements. The ARTA program is also a powerful analyzer of gated impulse response, smoothed frequency response (in 1/n-octave bands), step response, impulse response envelope (ETC curve), cumulative spectral decay curve, energy decay in reverberant environments, room acoustical parameters and speech intelligibility measures - STI and RASTI.
STEPS is a program for frequency response measurements with stepped-sine excitation. It offers possibility to measure the frequency response with high dynamic range and with high noise immunity (at least 30 dB higher dynamics than with a Fourier analyzer). Simultaneously with a
frequency response measurement the STEPS estimates levels of THD and higher harmonics.
Plot of frequency response, 2nd and 3rd harmonic distortion, measured with stepped-sine.